Plate heat exchangers are known in various designs. They include, in particular, sealed, soldered and welded plate heat exchangers. The various designs usually have in common the fact that a stacked arrangement is formed with a front-side and a rear-side end plate, between which a plurality of heat exchanger plates is accommodated and stacked, in such a way that cavities are formed between the heat exchanger plates, said cavities accommodating a plurality of heat exchanger media or fluids during operation. The heat exchanger media usually flow through the cavities.
Whereas sealing of the cavities takes place by means of soldered or welded joint in the case of the soldered or welded design, sealing elements are provided in the case of plate heat exchangers in a sealed design, said sealing elements being disposed in the stacked arrangement so as to seal the cavities. Sealed plate heat exchangers then comprise a clamping device, which is configured so as to pretension the stacked arrangement with end plates and heat exchanger plates as well as sealing elements, an external clamping pressure being exerted with the aid of the clamping device. FIG. 1 shows a perspective representation of a known plate heat exchanger in a sealed design, wherein a stack 3 with heat exchanger plates is disposed between two pressure frame plates 1, 2. The clamping device for pretensioning the stacked arrangement is formed by tension rods 4, which connect two end plates 1, 2 in overlapping regions 5. Tension rods 4 are provided with screw threads, so that an external pressure can be adjusted.